The invention concerns a plasma-operated cutting torch with contact starting. It is known that plasma operated torches are used for cutting metals. Typically a plasma fluid such as a gas is ionized by an electromagnetic field. Current flow in the form of an electric arc is then initiated. The electric arc is caused to strike between the electrode and the nozzle of the torch by means of a contact starting by high-frequency across a gap. The resulting flow of plasma streaming from the torch allows the performance of the cutting operation.
Contact starting torches are known wherein the electric arc is initiated separating the electrode from the nozzle by exploiting the force exerted by the gas to be ionized. This gas is pressurized and acts against a surface coupled to the electrode in the plasma chamber. Another known torch has the chamber to be pressurized separated from the plasma chamber. In such arrangements, the plasma chamber is blocked prior to contact starting and no gas flows. Thus, transfer of the arc to the work may be delayed or inhibited upon spark ignition. Also, debris may build up in the plasma chamber.
Known torches have complicated construction. Because of this complexity, the mechanism of the electrode is difficult to move.
Complex construction also entails another disadvantage, namely, that repeated use causes relative movement between component parts which, in the long run, prevents the torch from functioning consistently and reliably.